104 On Water Supply and Irrigation. 



" the vicinity, or from any other mine. When a diamond is 

 " brought to them, it is immediately handed to the eldest 

 " boy, who is tacitly acknowledged as the head of this little 

 " band. By him it is carefully examined, and then passed 

 * ? to his neighbour, who, having also inspected it, transmits 

 " it to the next boy. The stone is thus passed from hand 

 "to hand amid unbroken silence, until it returns to the hand 

 "of the eldest, who then asks the price, and makes the 

 " bargain. If the little man is thought by his comrades to 

 " have given too high a price, he must keep the stone on his 

 " own account. These children are so perfectly acquainted 

 u with the value of all sorts of gems, that if one of them, 

 " after buying a stone, is willing to lose one-half per cent, 

 " on it, a companion is always ready to take it." 



Art. XXVII. — On Water Supply and Irrigation. By 

 F. C. Christy, Esq., C.E. 



[Abstract of paper read 23rd November, 1863.] 



The author briefly noted a few of the chief causes of aridity 

 in Victoria during the summer months, and urged such 

 causes as reasons for storing the winter rains. 



The average of ten years' rainfall for Victoria is about 

 28 inches. The average rainfall in Melbourne for six con- 

 secutive years from 1840, was 26 '679 inches, The average 

 rainfall of Engiand is 26 - 6 inches. 



The following table shows the average for the Spring. 

 Summer, Antumn, and Winter months here and in Engiand. 



Prof. Neiunayer's 



S. Gibbons' 



Mean of 



10 Years' Obs. 



5 Years' Obs. 



England. 



Inches. 



Inches. 



Inches. 



Spring ... 9"! 5 



• 9-42 



4-929 



Summer ... 5*34 



4-58 



6-927 



Autumn ... 7 '6 5 



5-68 



9299 



Winter ... 7 "02 



8-26 



5-459 



The mean evaporation at Melbourne for the three years, 

 1860, 1861, and 1862, is 44517 inches. 



This amount of evaporation is less felt owing to' the 

 greatest rainfall in Victoria occurring during the months of 

 Winter and Spring, when the ground is moderately moist 



